Duplex letter sheet



Feb. 23, 1937. J. GIORDANO DUPLEX LETTER SHEET Filed May 5, 1955 FIG I FIG 2 INV ENTOR 9W 5 Patented Feb. 23, 1937 UNITED STATES PATENT OFFICE DUPLEX LETTER SHEET Joseph Giordano, Philadelphia, Pa.

Application May 3, 1935, Serial No. 19,660

2 Claims.

The invention relates to improvements in letter envelop page; the objects of which are; first: a letter page designed with inventive, mechanical, technological and scientific features forming a structure having three distinct and separate functions:

First, the letter envelope page folds into a single envelop having a writing page; a return envelop and writing page.

Second, the letter envelop page is separated into two letters, each having an envelop combined with writing page, and are distinct and independent of each other.

Third, the letter envelop page is separated or divided into two distinct units of sending envelop, return envelop, and writing pages. The envelopes are detachable and fold in a single and independent envelop.

I attain these objects by mechanism illustrated in the accompanying drawing, in which:

Figure l is a plan view of the letter envelop page, and also shows the interior view of the letter envelope page. Figure 2 is a view in perspective and also shows the back of the closed letter envelope page. I

Similar numerals refer to similar parts throughout the several views.

The letter envelop page has three distinct operations. Firstz-The entire letter envelop page comprising of sending and return letter consists mainly of parts I to 8 inclusive with lateral flaps H, II, II, II, and adhesive outlets l2, l2. The letter system is folded on lines (a) and cut on dented lines (b). Sec0nd:--The letter envelop page is divided into two separate independent letters on dented center line (11) each letter consisting of an envelop with'combined letter page. Thirdz-The envelopes are detached on dented lines (1)) separately, and independent of each other.

The adhesive outlets l2, l2, have triangular teeth 9, constituting a series of flaps (triangular) on the edge of the flap outlets (I) or (8). This reinforces the adhesive outlets and close strongly on destructive flaps 3 or 6.

The angle of rupture [0, reduces and controls theresilience of the flaps I-8 so that when the letter is opened rupture occurs at the vertex of angle of rupture l0, and follows the path of least resistance protecting the interior letter from rupture. When the letter is opened an external force is applied on flaps I-B. The internal resisting stresses are controlled by the angle of rupture In. The internal resisting stresses of the flaps l-8 are weakened and reduced at vertex of angle Ill and rupture is controlled on a limited and restricted area along the-path of least resistance on flaps I-8.

Number I is the flap of envelop with parts 2, face of envelop, H, H, lateral flaps of envelop, 3 destructive flap of envelop, with combined letter page 4, dented line (b) separates second letter page 5 combined with destructive flap 6 on dented line (b), secondary envelop consisting mainly of 1, face of envelop, 8 flap of envelop, II, II, lateral flaps of envelop, I2 adhesive area of flaps I-8, and 9, triangular teeth of outlets of flaps l-8.

The longitudinal bevel as shown on plan view Fig. 1 is 7/64ths of an inch to the linear foot. A tolerance of 3 /64 of an inch for folding is allowed on lines marked (a).

I claim:

1. A duplex letter sheet and return envelope, comprising two end sections each adapted to form the front of an envelope and a plurality of foldable intermediate sections adapted to form letter sheets, said intermediate sections being provided with weakened lines adjacent the edge of the end section, leaving a narrow flap permanently attached to the end sections, a second weakened line intermediate said first mentioned weakened lines, the end portions being provided with flaps on the other three edges thereof of sufficient size and proportions to form with said narrow flap the back of an envelope.

2. A duplex letter sheet and return envelope as defined in claim 1 in which the terminal flaps are provided with lateral triangles.

JOSEPH GIORADANO. 

